This paper engages in a critique of Italian and EU agricultural bio-waste policy, taking a relational approach to understanding the role of these materials in socio-material networks of production. Specifically, I consider how the challenges posed by excess materials of agricultural production fit into larger concerns about rural sustainability, both social and environmental. Drawing on a number of case studies from the Italian winemaking industry, I demonstrate the legislative creation of waste from the by-products of winemaking such as grape marc and vine wood. By physically removing bio-wastes from the socio-material context of their production, the current legislation privileges capital and technologically intensive methods for the management of bio-wastes. This process results in environmental contradictions and an unequal distribution of economic and societal benefits from the utilization of these materials. What is needed, I argue, is the incorporation of excess materials into thinking about local agro-ecologies as environmentally, economically and culturally sustainable.